Slower economic growth in China, India or other Asian economies would have a “serious negative impact” on Europe’s growth, the European Union’s economic chief said.

Olli Rehn, the EU commissioner for economic and monetary affairs, said yesterday in a Bloomberg Television interview that a slowdown in the U.S. recovery and turmoil in the sovereign debt markets also could cause concern in Europe.

Strengthening global growth helped Europe’s economy show the fastest expansion in four years in the second quarter after the Greek budget crisis earlier damped confidence in the euro currency and forced governments to step up deficit-cutting measures. Euro-area growth is likely to decelerate in the second half of the year as signs of a slowdown in the U.S. and China dim export prospects.

In the U.S., the world’s biggest economy, the Commerce Department may revise lower its second-quarter growth rate to the slowest since the recovery began, according to the median forecast of economists in a Bloomberg News survey. China’s expansion eased to 10.3 percent in the second quarter and industrial production cooled more than forecast in June, data showed last month, signaling a deeper second-half slowdown.